Hi there :)
The Popup window to chose a date for a Task shifts the dates per month by one day to the left.
For example:
As you can see, the 10th of March should not be labled as monday. It is a tuesday.
The Forecast section in the Task Genius View shows this date-day-mapping correctly:
Thank you very much for fixing and for your cool plugin. Adds a lot of additional value to Obsidian :)